The purpose of this project is to examine the relationships between early adolescent daily experience and psychological adjustment in early, middle and late adolescence. Numerous scholars have hypothesized that the changes of early adolescence make it a critical period for the development of mental health or illness. This project evaluates this hypothesis, giving special attention to daily experience and the daily ecology of adolescent life, including patterns of day-to-day stress and teens' ongoing strategies of coping. The project is a continuation of a study in which 505 randomly selected 5th to 9th graders provided 19,000 reports on random moments in their lives. Following the procedures of the Experience Sampling Method (ESM), these older children and young adolescents carried pagers for one week and reported on their situations and internal states in response to signals sent via the pagers. In addition, a sample of 112 mothers and fathers (56 families) carried pagers and provided ESM self-reports concurrently with their adolescent children. The new proposal includes further indepth analyses of these existing data, examining the relationship of adolescent adjustment with: a) the experience of daily positive and negative events, b) patterns of affect with parents and peers, c) involvement in sports and other organized leisure activities, d) television viewing, e) maternal employment, and f) the moods and activities of teenagers' parents. In order to study the relationships between early adolescent experience and adjustment in middle and late adolescence, two new longitudinal data collections will be conducted with members of the original sample. The "Biennial Data Collection," carried out at the University of Illinois at Urbana, will obtain systematic follow-up information on all of the students at intervals 2, 4, and 6 years after their original participation. The "Rebeeping Data Collection," carries out at Loyola University, will obtain a second set of ESM data on approximately 300 students at a point 4 years after their original participation, giving special attention to processes of daily coping. These longitudinal data will allow us to study trajectories of individual change and evaluate hypothesized paths of causality between early adolescent stress, daily experience, and the development of positive adjustment or psychopathology.